This invention relates to closure members for vehicles which close a compartment such as a tailgate, a cargo door, or a sliding door or the like. The door is typically moved, for example pivoted or slid from a closed position to an open position. In order to effect this movement, a handle must be operated through a control assembly to release the latch mechanisms allowing the closure to be moved to the open position. This present invention finds particular application therefore in providing such a control assembly which has simplified the structures heretofore known reducing the number of parts thereof and increasing the reliability thereof while reducing the overall power consumption required in a preferably power actuated control assembly.
Within the prior art there exists a number of structures for releasing a closure such as a tailgate. For example, U.S. Pat. No. 5,531,498, as one example, refers to a power lift-type tailgate and includes a control assembly which is cable driven once the latches are released. The drive includes a motor driving a cable reel to lift the tailgate assembly.
Other designs are also known, which designs have been installed on the lift gates of certain production vehicles. These designs include an actuator which converts linear motion to a rotary motion for the locking lever, and then through the two-position floating pin to a further linear motion of the floating pin to a rotary motion for the output lever to a further linear motion for the cable release. A significant amount of friction therefore is developed, and hence friction loss is experienced as a result of utilizing such a system. Incorporated with the locking lever is a two-position over center toggle spring which allows the two positions attained by the floating pin. The locking lever has an emergency manual override tab which may be accessed should the actuator fail. Therefore, when the input lever is operated by a handle connected to the control via a rod or a cable, the input arm of the input lever will engage the floating pin and therefore allow release of the latches. Should the floating pin however be moved via the operation of the locking lever to the inoperative position, then the input arm of the input lever will not be able to access the floating pin, and hence the output lever will not operate in spite of the fact that the input lever will operate. Such a control assembly therefore includes a first pivot connected to the locking lever, a second pivot connected with the floating pin, a third pivot about which the locking lever pivots, and a fourth pivot about which the input lever and the output lever pivot. Within the actuator itself, it is estimated that the electrical requirements would be approximately 10 watts normally, and peak at approximately 50 watts or more, with up to 5 amps being drawn by the motor.
Clearly therefore, the problems can be seen in providing such a device in that a significant amount of the power utilized by the actuator goes into friction losses when transferring the power from the actuator to the actual cables. Secondly, the reliability of the product must be questioned in that many of the parts, for example such as the tab from the locking lever which accesses the opening of the linear actuator plunger, undergoes a dynamic load over each cycle and may tend to fail in time. Secondly, the pivot for the locking lever may tend to bind in time, or the floating pin may also bind within the slot between its two positions.
The disadvantages of the prior art may be overcome by providing a latch control assembly having a simple mechanism for locking and unlocking a lift gate or door and for effecting unlatching thereof.
According to one aspect of the invention, there is provided a control assembly for releasing a latch. The control assembly has a base plate for mounting components of the control assembly. A pivotally mounted input lever is movable between a ready position and a release position. The input lever connects to a release handle. A pivotally mounted output lever connects to a latch and transmits a releasing force. A pivotally mounted locking lever is rotatable between a locked position and an unlocked position. A link slidably engages the output lever and pivotally engages the locking lever. When the locking lever moves between the locked and unlocked positions, the link responsively decouples and couples the input lever and the output lever to allow independent and dependent rotation thereof, respectively, selectively transferring the releasing force from the release handle to the latch.